1. Field Of The Invention
The present invention relates to an image forming system. Specifically the system relates to an image forming apparatus capable of halftone correction and a half tone correction method.
2. Description Of The Related Art
Conventional image forming apparatuses are known which are capable of forming images having halftones. In such image forming apparatuses, there are occasions when halftone correction is required due to the characteristics or condition of components within the apparatus. Halftone correction is typically accomplished by applying a calculation based on two image forming steps. In one step, a predetermined halftone pattern is recorded onto a recording sheet. In another step, the predetermined pattern is read off of the recording sheet.
When correcting halftones, a user must typically operate the image forming apparatus such that a predetermined pattern is recorded onto a recording sheet. The recorded pattern is then read using an image reader which is typically incorporated into the image forming apparatus.
Japanese Laid-Open Patent Application No. 8-25654 discloses an apparatus in which erroneous user-performed operations are avoided when correcting halftones. The image forming apparatus displays the various operations and sequences of halftone correction using a display unit. By displaying the halftone correction operations along with the proper sequencing steps, the apparatus assists the user's tasks.
When the predetermined pattern is printed onto a recording sheet and the sheet is subsequently placed at a predetermined position in an image reader unit to read the pattern printed thereon, a user may erroneously place the sheet at an unsuitable reading position. In conventional image forming apparatuses, the printed pattern is read regardless of whether the sheet is placed in an unsuitable reading position. Furthermore, there is no provision for safeguarding against this type of erroneous user operation. As a result, the pattern printed on the sheet must be re-read by the image reader unit after the user suitably replaces the printed sheet at the appropriate reading position.
An object of the present invention is to avoid the previously mentioned disadvantages by providing an image forming system capable of avoiding repetitive halftone corrections by a user.